System of mineral treatment for recovering rare metals



c. B. ULRICH 2,086,322 SYSTEM OF MINERAL TREATMENT FOR RECOVERING RARE METALS July 6, 1937.

7 Sheets-Sheet 1 Filed Jan. 16, 1933 INVENTOR.

' CHARLES B. ULRICH "W E I mm. wm kw 3% N mJr nl. .1 NH.. 1H

, ATTORNEY.

July 6, 1937. I c ULRICH 2,086,322

SYSTEM OF MINERAL TREATMENT FOR RECOVERING RARE METALS Filed Jan. 16, 1933 7 Sheets-Sheet' 2 INVENTOR.

' CHARLES B. ULRICH NW (Z.

ATTORNEY.

July 6, 1937. c; cH 2,086,322

SYSTEM OF MINERAL TREATMENT FOR RECOVERING RARE METALS Filed Jan. 16, 1933 7 Sheets-Sheet 3 INVENTOR. CHARLES B. ULRICH um-J6.

ATTORNEY.

July 6, 1937. T c u mc 2,086,322

SYSTEM OF MINERAL TREATMENT FOR RECOVERING RARE METALS .1 56g I 8 INVENTOR.'

55 CHARLES B. ULRICH c g q aa 6.

ATTORNEY.

July 6, 1937. c. B. ULRICH 2,086,322

SYSTEM OF MINERAL TREATMENT FOR RECOVERING RARE METALS Filed Jan. 16, 19.33 7 Sheets-Shet 5 Eyes H m-Z INVENTOR. CHARLES B. ULRICH WW6 M ATTORNEY.

July 6, 1937. c. B. ULRICH 2,086,322

SYSTEM OF MINERAL TREATMENT FOR RECOVERING RAE METALS Filed Jan. 16, 1933 V 7 Sheets-Sheet 6 F 69a, B96 1694) A39 5/6 5/6 I INVENTOR.

5/ CHARLES B. ULRICH ATTORNEY.

July 6, 1937. c. B. ULRiCH 2,086,322

SYSTEM OF MINERAL TREATMENT FOR RECOVERTNG RARE METALS Filed Jan. 16, "1933 7 Sheets-Sheet 7 INVENTOR.

1 CHARLES B. ULRICH /WZS.

ATTORVE Y.

Patented July 6, 1937 I UNITED STATES Y Q -i v Application .lanuary 16, 1933, Serial No. 651,887

21 Claims.

My invention consists of improvedmeans for treating minerals to recover the precious metals therefrom, by different treatments adapted to the different metals to be recovered and adapted also to the different sizes of the pieces or-particles of the metals as they exist in the mineral being treated, as well as the method of treatment involved. By my invention I much more effectively recover the values than where the mineral is subjected to but one kind of treatment to recover the values therefrom.

My, invention is described herein, in connection with placer mining, but it will be understood that it is equally applicable to the treatment of mineral matter mined in other ways and prepared for the recovery of valuable metal or metals therefrom, in any manner-that may be necessary or desirable, depending upon the nature of the mineral matter, and whether it is free milling or not. I In placer mining in the past, the water and broken up mineral, having generally been 'deliv- The procedure just stated, is open to the disadvantage that on account of the water flow in the sluiceway being generally rapid, unless the metal particles are large enough to drop through the water against its fiow, they are carried by the stream over the riilles and delivered fromthe tail end of'the sluiceway with the waste mineral matter carried by the water stream. As a result, the treatment heretofore employed has been quite ineflicient. This is due to a variety of 'causes, among which. may, be mentioned, first, the sanding, or filling with sand and'fine mineral, of the recovery compartments in the sluiceway, and

second, the entire lack of means for recovering the fine metal particles of value, held in suspension-with the other suspended material in the water flow. v Y g By my invention, I provide apparatus anda method of treatment of the mineral matter delivered to the system for treatment, which, regardless of the nature of the mining and pre- 5 liminary treatment employedto prepare the mlneral matter for the recovery of valuable metalparticles therefrom, classifies the metal and min-- eral particles accordingtd siza-and then applies" to the metal particles of each "size, arecovery treatment particularly adapted to metal particles of that size, and by my invention, I also classify separate from each other and recover metal particles that are readilysusceptible of amalgama-" 7 tion with mercury, metal particles'that' do not readily so amalgamate but which will do so when lsuitably treated and metal particles thatwill not so amalgamate under any conditions; 'B'y'm'yin vention, I effectively recover from mineral matter, not only the more common of the valuable metals, such as gold, silver and platinum, but also the rare metals, such as iridium, palladium,ruthe-' nium and osmiridium. 'I'he several classifica- V tions of mineral are preferably treated in corresponding stages, and each stage of treatment may 4 consist of as many treatingsections'as required.

In connection with'placer mining} I flndthat the pieces or particles. of metal desiredto berecovered, exist indifferent forms and sizes," as they are delivered with the water to the sluiceway. Generally'speaking, these pieces or particles may be given three classifications,;first; the piecesor j particles of large enough size to drop positively 25 through the water stream iii-the sluiceway; so that they will move-along the bottom wall of the sluiceway and engage whatever meansmay be employed to collect them from the mineral and water flowi'ng through the sluiceway, which 30 pieces or particles for convenience may be referred to as coarsemetal particles'i'se'c'ond, pieces or particles ofmetal smallerthan the coarse metal particles, and which on account of their smaller size, are carriedsomewhat freely by the' water stream, so that they'do notsettle through the water as readily as do the coarse metal particles, but which, if given' ashort time, will find their way to'the bottom of the sluiceway, particularly if there are .no' eddy currentsset up'in'the water flow, for'example as produced by rifiles,

which pieces or particles may'for convenience be called medium metal particles; and'third, particles of metal.smaller than the medium metal particles and so fine that they willnot settle through the water; s tream, even if given acomparatively' long time-to do so, but which on the other hand mayfbe carried by. the. waterrfiow throughout the entire length of the sluiceway,

- fine metal particles.

which particles for "convenience may be called 50 'Bymy invention, as appliedto, placer mining, I- provide in connection withthe main sluicewayggi,

first devices for diverting or'by-passing from the flow of the main sluiceway, the coarse metal par- 55 Zil ticles and subjecting them to amalgamation under conditions adapted to the size of said particles;

also, second devices for diverting or by-passing treatments adapted to the size ofsaid particles;

also, third devices for collecting and delivering the fine metal particles to recovering treatments adapted to the small size of said particles; and

also further devices for collecting and retaining the fine particles of metal not previously collected, particularly the particles of rare metals, so that they will not be lost. In this way, I provide a treatment for each class of metal particles, which is adapted to recover that class of particles from the water and mineral delivered to the main sluiceway, and as a result, the efllciency of operation of my system is relatively great, it being not unusual to recover several times as much value from the mineral being treated, as has been possible with placer systems heretofore employed. By my invention I also enclose the value recovering devices associated with the main sluiceway, so that they cannot be reached or disturbed during the flow of water through the main sluiceway, and in this way I prevent theft of the recovered metals. The other treatment devices provided for by my system, after the mineral to be treated has left the main sluiceway, may also be protected against theft, by enclosing them in suitable shelters or sheds.

By my invention, in connection with the diversion of water from a sluiceway as referred to, I provide means for returning all of the diverted water to the flow in the sluiceway, when it leaves the corresponding treatment section and before the next diversion of water and mineral from the sluiceway. This maintains a practically uniform water flow in the sluiceway where such treatment sections are employed, which is desirable, particularly in connection with placer mining, since the effective movement of large pieces of mineral,

- and other material if-it gets into the sluiceway,

depends upon the maintaining in the" sluiceway of a rapid flow of a sufllcient quantity of water to eilect such movement.

My invention will best be understood by reference to the accompanying drawings, illustratinga. preferred embodiment thereof, in which so Fig. 1 is a diagrammatic plan view to a small scale, of a main sluiceway of a placer system, associated control tanks and auxiliary treatment devices for effecting the'operationsreferred to,

Fig. 2 is a plan view to an enlarged scale. of the upper end portion of the main sluiceway, illustrating the devices employed for diverting coarse metal particles from the main sluiceway,

Fig. 3 is a vertical, sectional viewof the parts shown. in Fig. 2, taken alongthe line 3-8.

Fig. 4 is a vertical, sectional view to a further enlarged scale of the construction illustrated in Fig. 3, taken along the line 4-4,

Fig. 5 is a plan view to a scale larger than that used in Fig. 1, of the portion of the main sluiceway involved in diverting medium meta particles from the main sluiceway,

Fig. 6 is a vertical, sectional view of a part of the construction illustrated in Fig. 5, taken along the line. H, the lower part of this'flgure illustrating in similar view, another part of the construction shown in Fig. 5' taken along the line la-ia. theentire view shown in Fig. 6 being .9 taken along the line 8- in I'll. 7,

m. 1 as vertical, sectional view a; s ammroller grizzly located'at the lower end of the main Fig. 6, taken along the line 'll,

Fig. 8 is a vertical, sectional view to an enlarged scale, of a part of the construction shown in Fig. 1, taken along the line 88, the upper por-- 5 tion of the parts shown in this figure having their side walls adjacent the observer removed, to more clearly illustrate the structure involved,

Fig. 8a illustrates in a view similar to Fig. 8, a part of the construction of one of the control tanks, this view being taken along the line flit-4a in Fig. 1,

Fig. 9 is a vertical, sectional view of the construction illustrated in Fig. 8, taken along the line 9-8,

Fig; 10 illustrates in plan view to a larger scale than that used in Fig. 2, the portion of the upper end of the main sluiceway involved in one section of treatment of the coarse metal particles,

Fig. 11 is a vertical, sectional view of the parts shown in Fig. 10, taken along the line I l-l I,

Fig. 12 is a horizontal, sectional vlew of the parts shown in Fig. 11, taken along the line "-12,

Fig. 13 illustrates in plan view, to a further enlarged scale, one of the rifle blocks preferably used in connection-with the devices illustrated in Fig. 12,

Fig. 14 is an edge view of the rifle block illustratedin Fig. 13, 7

Fig. 15 is a vertical, sectional view to a further enlarged scale, of the rifle block illustrated in Fig. 13, taken along the line I5--|l, Fig. 16 illustrates in plan view and to a larger scale than that used in Fig. 5, one of the sections of themain sluiceway involved in diverting medium metal particles from the main sluiceway,

Fig. 17 is a vertical, sectional view of the construction illustrated in Fig. 16, taken along the and bottom plates illustrated in Figs. 19 and 20,

Fig. 22 is a horizontal, sectional view of a part of the construction illustrated in Fig. 18, taken along the line 22-42, and shows in plan view one 55 of the rifle boxes employed to collect the medium metal particles,

Fig. 23 illustrates in plan view and to a scale larger than thatused in Fig. 1, a part of the sluiceway,

Fig. 24 is a vertical, sectional view of the parts illustrated in Fig. 23, taken along the line 24-24, Fig2.325 is a'side elevation oi the parts shown in Fig.

Fig. 26 is a horizontal, sectional view to an enlarged scale, of a part of the construction illustrated in Fig. 8, taken along the line "-28, and shows one of the rifle boxes employed tocollect and retain the fine metal particles, electrical connections and electrodes not shown in Fig. 8, being illustrated in this figure, which may be used, if-desired, to'electrically' charge the metal particles flowing through the rifle box,

Fig. 2'! is a vertical, sectional view to a fur-: 75

ther enlarged scale, of a part or the construction illustrated in Fig. 26, illustrating a means that may be employed to supply fresh water to any of the riflle boxes,

Fig. 28 shows in vertical, sectional view to a trated in Fig. 1, which is remote fromthe main sluiceway, and troughs for directing the overflow from said control tank to special sluiceways for recovering the fine metal particles not previously collected, and particularly the fine particles of rare metals,

Fig. shows in plan view to a further enlarged scale, the admission end of the special sluiceways illustrated in Fig. 29, v r

Fig. 31 is a vertieaLsectional view to a still further enlarged scale, of the construction of one of the special sluiceways illustrated in Fig. 30, taken along the line 3|-3|,

Fig. 32 shows in-plan view and to an enlarged scale, a portion of one of the grids employed in the riiile boxes illustrated in Fig. 1'7, r

Fig. 33 is a vertical, sectional view of the structure illustrated in Fig. 32, taken along the line 33-33,

Fig. 34 shows in bottom view and to a scale larger than that used in Fig. 17, an adjustable gate for controlling the amount or flow of water and particles of minerals and metals, to each of the rifiie boxes illustrated in Fig. 18, this view being taken along the line 34-34 in Fig. 17, the associated transverse trough being removed,

Fig. 35 is a vertical, sectional view to a scale larger than that u'sedin Fig. 26, of the construction illustrated in Fig. 26, taken along the line 35-35,

Fig. 36 is a vertical, sectional view to a further enlarged scale, of a part of the construction shown in Fig. 35 taken along theline 3636,

Fig. 37 illustrates in plan view, a part of one of the distributing troughs shown in Fig. 9,

Fig. 38 is a side elevation of the parts shown in Fig. 37,

Fig. 39shows in a view similar to Fig. 13, a modified construction of rillle block,

Fig.- 40 is a lower edge view of the riflle block illustrated in Fig. 39,

Fig. 41 illustrates in plan view a locking rod for use in holdingin place, riiile blocks of the construction-illustrated in Figs. 39 and 40, i

Fig. 42 illustrates in plan view and tom enlarged scale, a part of the riille box construction illustrated in Fig. 1'7, this .view being taken along the line 42-42 in Fig. 17,- i a Fig. 43 is a vertical, sectional view to a further enlarged scale, of a part oi! the construction shown in Fig. 42, ,taken along the line l3-43,

Fig. 44 illustrates in a view similar to Fig. 11,

' a construction similar to that shown inthat Hand I2 along its sides.

ence, the main sliceway is dividedinto sections In Fig. l, I illustrate'the main sluiceway of .a

placer-mining system at l0, provided with walks For'convenient refer- A to L, the section A being at the upper end of the sluiceway receiving the water and mineral. from the mineral body, and the section L being at the lower or discharge end of the sluiceway.

The sectionsA, B and C are involved in the treatment of coarse metal particles, the sections D, E, F, G, H, and J are involved in the treatment of medium metal particles, the section K is a connecting section, and the section L includes at its lower end, a roller grizzly for diverting the water and fine metal particles to the control tanks l3 and I4.

Each of the control tanks l3 and H is provided with discharge pipes l5 and I5 extending downwardly from its bottom wall, which carry water and metal particles from the control tank to rifile boxes I1 and Hi, the riille boxes I! not being shown in Fig. 1, since they are below the corresponding riii'le boxes I8. The control tank I3 is provided with gutters l9 and 20 along its sides,

for receiving the overflow from the. tank, and the control tank I4 is providedwith similar gutters 2| and 22. The gutters l9 and 20, as more clearly shown in Fig. 29, deliver their contents to troughs 23 and 24 which in turn deliver the water and metal particles to special sluiceways 25 and 26. The gutters 2| and 22 similarly deliver their contents to special sluiceways 25a and 26a corresponding to the sluiceways 25 and 26.

It will be noted that a plurality of rliile boxes iii are shownfor each of the control tanks, representing difierent sections of treatment of material delivered from the control tanks, these sections being numbered for convenience from I-XII for each control tank. As a result, the

water and metal particles delivered to each control tank are subdivided, and flow to the several treatmentsections, and on account of the number of treatment sections employed -the flow is of sufliciently reduced-rapidity so that the material maybe efiectively treated in eachof the riilie from the treatment of material in sections D to J of themain sluiceway, to -a chute below the grizzly 29, for delivery to thespouts 21 and 28 as described below. i e y As illustrated in Figs. 2 and 3, each of the treat,- ment sections A, B and C of the sluiceway I0 is provided adjacent its upper end, with a stationary grizzly 3| in the bottom" of the sluiceway, from which the said bottom continues downwardly in the form of transverse metal plates 32, to a more sharply inclined inetal' delivery plate 33 which directs. the water and mineralv matter carried by it, upon the upper portion of the bot- A tom of the main sluiceway at the upper :end of the next treatment section. Each delivery plate 33 delivers the material'flowing upon it, over a metal bar 49 which is sufliciently above the bottom of the sluiceway below it, to permit the water and mineral delivered from any one of the sections of treatment, to flow below said bar to the next stationary grizzly 3|, or from the last of said treatment sections, to the first or the next succeeding treatment casemaybev As illustrated in Figs. 3 and 11, the bottom sections, D, as'the plates 32 of each of the treatment sections, A, 7

II- and I! to the main sluiceway l0, and the relation of each of the rifle boxes 34 to the bottom of small amount of water flow from the sluiceway I- the main sluiceway. I sluiceway l0, the walks ii and I2 and the supporting members for the various parts referred to,

are preferably of wood, to facilitate the constructionof the parts of the system and to make the structure relatively inexpensive.

From the operation described in general, it will be observed that pieces oi mineral of small enough size to pass through each of the grizzlies 3|, including the coarse metal particles, and a part of the water flowing through the main.

sluiceway iii, are diverted or by-passed from the main flow in the sluiceway, for treatment of the coarse metal particles in'the corresponding rifle,

box 34, and that this is repeated as many times as may be necessary or desirable, to eflect a high percentage of recovery of the coarse metal particles, the unretained metal and mineral in each case flowing with the diverted water, and with the fresh water if it is added, to the next treatment section, and finally from the last treatment section C to the first treatment section D of the-next stage of treatment to which the mineral is subjected.

' As'iliustrated in Figs. 5, 6, 16 and 1'7 the bottom of the main sluiceway ID for the treatment sections D to K, and for the first part of the section L, consists of transverse metal plates 33, provided with restricted passageways around their edges, in a manner to be described, to-permit a around the edges of each of said plates, carrying with it medium metal particles, which diverted water and metal particles arereceived by a, rifle trough 31 below the sluiceway, said trough having buck boards or partitions 33 across it at intervals corresponding with the lengths of the treatment sections E to J, so that the medium metal particles collected between any two adjacent partitions 33, or above the uppermost one of said partitions, are directed from just above each partition 33, through a trough 33 into a rifle box 43 for treatment therein in a manner to be described, each of said rifle boxes delivering therefrom the water and mineral not retained by said rifle box, into a rifle drain 4|. A pipe 42 is provided for each of the rifle sections of the trough -31, to'supplyiresh water thereto as may bedesired, and each of the rifle boxes 43 is provided with a pipe 43 for supplying fresh water thereto, as may be desired to produce most effective results in said rifle box. v

As illustrated in Fig. 7. the trough 31 is below the bottom plates 33 of the main sluiceway l3, and the rifle boxes 43 and also the rifle drain 4i, are below the walk II, and each trough 33 extends laterally through'the side wall of the .housing of the main sluiceway II, to deliver water and mineral from the corresponding section of the trough 31. to one of the rifle boxes 43. The rifle drain 4i extends to the lower end of the walk II, where it deiiversthewaterflowinginit The side walls of the main.

and the mineral carried thereby, into the trough 3B shownin Fig. 1.

The several sections of the trough 31 are pro-" vided with means for collecting and retaining fine metal particles in'a manner to be described, so that said trough sections besides supplying the rifle boxes 40 with material for treatment, alsoconstitute rifle boxes.

In Figs. 10, 11 and 12, I illustrate one way in which each of the treatment sections A, B and C of the main sluiceway I I) may be constructed.

In Fig. 10, the same parts of the sluiceway are illustrated as shown in Fig. 2, excepting that they are to a larger scale. As shown in Fig. 11, the metal bottom'plates 32 are supported on longitudinally extending'planks 4,4, which in turn are supported by cross beams 45, the ends of which rest in flanged metal brackets 46 carried by the side walls of the sluiceway. The delivery plate 33 is similarly supported, excepting that its lower edge is carried directly by flanged metal brackets 41 carried by the side walls of the main sluiceway, to reduce the over-all height of the structure. Each oi. the grizzlies 3| consists of transverse metal bars separated by amounts cor-v responding to the size of the coarse metal particles to be permitted to pass through the grizzly, and just above each of the grizzlies 3| except the grizzly adjacent the extreme upperend of the sluiceway, the bottom of the sluiceway is covered, for example, with a thick sheet of rubber 48, to

- cushion the impact on the bottom'ofthe main sluiceway, of heavy piecesof mineral that may drop from the next upper sluiceway section. To facilitate replacement due to wear, a transverse metal bar 43 is preferably carried by the brackets 41 immediately below the lower edge of each delivery plate 33, so that. renewals may be more readily made than if it were required to renewvthe entire delivery plate 33, and furthermore the bar 43 a may be made of hard metal, for example, manganese steel, if desired, without. incurring the expense that would be involved if the entire de- 'livery plate 33' were made of such metal,

although, if preferred, the plates 33 may be made of such material and the bars 49 may be omitted.

The rifle box 34 illustrated in Fig. 11, consists of longitudinally extending planks 50 supported by suitable wooden cross beams, and on the planks, a plurality of rifle blocks 5i are mounted,

the upper end of the rifle box 34. just above the uppermost rifle blocks 5|, being provided with a sand box 52 to receive the water and mineral delivered to the rifle box through the grizzly 3|,

and to avoid the undue wear that otherwise would .result from the pieces oi mineral striking the upper portion of-the bottomof the'rifle box.

The rifle blocks M are pr ierably constructed ,as will be described, to con n mercury for amalgamating the coarse metal particles which pass downwardly on said rifle blocks towards the next section 01' the bottom 01 the sluiceway. A t the. lower end of each rifle box 34, a.metal sump I3 is provided, to each and retain any oi the mercury that may be displaced from the rifle blocks L The rifle blocks 5| are somade that the mercury is not readily displaced from them.during their operation, and the sumps 53 are provided as a precautionary measure, to insure that any mercury that may be accidentally dislodged from said blocks. will not be lost. Below each sump 33, a metal plate 34 constitutes the upper part of the next section oi the bottom of the main sluiceway II. which metal plate extends down to the upper edge of the rubber plate ,the latter being "73 said section, under the lower end of the next upper one of the sections A, B and C, said rails under the lower edge tially so.

In Figs. 44 and 45, I illustrate a different construction for receiving the impact and wear of large size pieces of mineral dropping from the lower endof each of the sluiceway sections A, B and C. In this construction, instead of the rub-.- ber sheet 48, I place a plurality of short lengths of steel rails 48a, longitudinally of a lower one of the sluiceway sections and at the upper end of of the bar 19, or substan being preferably placed as close together as their flanges will permit, and covering the entire width of the sluiceway. The rails receive the impactsof pieces of mineral dropping upon them from the next upper sluiceway section, and transfer said impacts to the supporting planks and timbers of the sluiceway structure, and. the spaces between the heads and webs of said rails, provide passages for the free flow of water and mineral from the rifle boxes respectively delivering material to them. The rails are readily renewable when worn and are inexpensive to install and maintain, since used rails which are too badly worn to be used for track work, are quite satisfactory for this purpose.

As illustrated in Fig. 12, the rifle blocks 5| are preferably of relatively small size, for convenience in manufacture and handling, whereas the width of the main sluiceway I0 and of the rifle box 34 below it, may be relatively large, requiring a plurality of riiile blocks to complete the width of the covering of the bottom of the rifle box. In

view of this, and of the further fact that the length of the rifle box requires a plurality of transverse rows of said rifle blocks to cover its bottom, it is desirable that the longitudinal joints between the rifleblocks shall be broken for successive transverse rows thereof, and to facilitate this, I employ half blocks, as indicated, at the ends of intermediate ones of said transverse rows -of blocks; the corresponding end blocks of the alternate rows of said rifle blocks being full size blocks. a

In the stage of treatment illustrated by sections A, B and C, it will be observed that a part of the water flowing in the main sluiceway, is diverted therefrom for each of said treatment sections, but that the water so diverted for any of said treatment sections, is returned to the sluiceway beforethe next of said diversions from the sluiceway is effected. This is important where large size pieces of mineral or other solid material must be moved by the water flowing in the sluiceway. In such cases, a certain minimum amount of flow is necessary, in order to effectively move the solid matter in the sluiceway, and any permanent diversion of a substantial amount of water from the sluiceway, results either in leaving too little water in thesluiceway to effectively move the solid matter therein, or in requiring an excessive amount of water to be supplied to the upper end of the sluiceway, and excessive flow above the point of permanent diversion] By my invention, the flow in the sluiceway isnot seriously decreased by the diversion through the grizzlies 3|, since said decrease is no greater at any point in the sluiceway than that produced by the diversion through one of the grizzlies 3|, which may readily be adjusted to suitthe requirements of any particular case, by using a corresponding number of bars in said grizzly, the said diversion being proportional to the number of bars used in the corresponding grizzly. Furthermore, the return of the diverted water to the sluiceway after each diversion and before a succeeding diversion is effected, results in reestablishing full, normal flow in the sluiceway after each of said diversions. vantages'of diversion from the sluiceway, withadvantages being that the sluiceway may be constructed entirely for the purpose of effectively moving solid material in it, for example, it' may have a greater slope than it could have if metal recovering operations were affected in it, that the devices provided for handling the diverted flow may be constructed entirely for the purpose of eiTectively recovering metal particles from the diverted material, and that the metal recovering means may be enclosed and rendered inaccessible while the sluicewayv is in operation.. i

In Figs. 13, 14 and 15, I illustrate one manner in which I may construct the rifle blocks 5| referred to. Each rifle block 5|is preferably square or rectangular, and is provided with a plurality of parallel grooves 5|a extending nearly from the top edge to the bottom edge across the top surface of the block, as illustrated in Fig. 13, so that each groove may contain mercury for amalgamation purposes, independently of the other grooves and independently of the other rifle blocks. As illustrated in'Flg. 15, each of the grooves lila has a depth substantially more than half the thickness of the block 5|, and isprovided on the side against which the flowing water strikes, with a sharp edge 5|b from which the groove is provided with a cylindrical, concave wall to the bottom of the groove, so that the edge 5|b extends over a part I thus secure the ad out involving the system in disadvantages, 'said of the groove, the remaining wall' oi the groove being convex and gradually merging with the top surface of the block 5|, so that the upper part of the groove is substantially wider than its lower part. The block 5| may be provided on two of its outer edges, with grooves ilc and on its other edges with corresponding tongues Bid, so that when the rifle blocks are assembled on the bottom of a rifle box, as illustrated in Fig. 12, the tongues and grooves of adjacent blocks interengage each other. The blocks 5| may be made of any material that will eflectively hold mercury, for example, cast iron or rubber, an important consideration being that the material shall be inexpensive on account of the large number-of blocks used in the system.

In Figs. 13 and 15, I illustrate metal studs file rare metals which do not readily amalgamate with mercury unless electrically charged. Where the 'blocks are made of rubber, they are preferably made in molds, and the studs 5| e may either be molded in place in the blocks, or corresponding holes may be formed in the blocks,-and the studs Where the latter practice is followed, it is (16811!- able to provide the studs with flanges and thin heads as shown, or the equivalent, topositively hold the studs in proper position after they are inserted, and to seal the holes through the blocks,

- so that there will be no mercury leakage and that the lower ends ofthe studs as'shown in Fig. 15,

' may be inserted after the blocks are molded.

70 and fine metal particles are carried through the may readily make electrical contact with a metal connector or connectors.

In Figs. 39 and 40, I illustrate a construction of riille block I5I for the same purpose and operat ing in the same manner as the riille block 5I, but having a different construction for interlocking the edges of the blocks while they are in use. The edges or. the blocks are provided with grooves I5Ic, which may extend entirely around them, or

be formed only in their opposite edges, as desired, and when these blocks are in use, they may be held in place by rods I52 of suitable material, for example iron or steel, illustrated in Fig. 41, in the aligned grooves of adjacent blocks. It will be understood that the edge interlocking constructions illustrated in Figs. 13 and 14 and in Figs. 39 and 40 may be used as shown, or in any desired combination, and that different arrangements of the blocks may be employed, as desired, to suit the requirements of different cases.

In Figs. 16 and 17, I illustrate therelation of the bottom plates 36 of the main sluiceway ID, to each other, and the location of the troughs '39 below said plates and the walk II. As shown in Fig. 16, the plates 35 are separated by intermediate supporting bars 55, provided as indicated in Fig. 1'7, along their lower edges with outwardly extending flanges, each of the bars 55 being provided as indicated in Fig. 16 at its ends, with a bent metal spacing member 55, to slightly separatethe plates 35 from the supporting bars 55, excepting at their end portions. The construction of the spacing members 55 is more clearly shownin Fig. 21, where one of said members is illustrated in perspective view, and in Figs. 19 and 20, where one of said members '55 is shown in place on the'end of one of the supporting bars 55 in position to support the corresponding end por tions of-the adjacent plates 36. Each of the supporting bars 55 may be provided with a groove 55a in its upper surface, similar in form to the grooves 5Ia formed in the riflle blocks 5|, to contain mercury and constitute a riille bar across the bottom of the main sluiceway to engage and retainsuch particles of metal susceptible of amalgamation, as come in contact with said mercury. The riille grooves in the bars 55, may be employed or not, as desired, depending upon the conditions under which the structure is used.

From the construction just described, it will appear that a restricted passageway is provided between each of the supporting bars 55 and each adjacent bottom plate 35, the thickness of this passageway depending upon the thickness of the sheet metal from which the bent spacing members 55 are constructed.

The bars 55 may be supported at their ends from the side walls of the sluiceway 10, by bars or brackets not shown, permitting the ready removal of said bars for the purpose below described, for example, by brackets like the brackets 41 above described.

It is to be borne in mind, that by the time the mineral carried by the water in the main sluiceway, passes over the lower portions thereof, represented by sections D to L inclusive, the coarse metal particles susceptible of amalgamation, have been removed by the preceding treatments-illustrated and described for sections A, B and C of the main sluiceway, and that only the medium remaining sections of the sluiceway. It will be observed that the main sluiceway is provided for a considerablelength, with a bottom con the medium metal particles have opportunity to settle through the water flowing in the sluiceway. even though the flow may be rapid, which is ,cated as above described, below the sections D to J inclusive, said trough being illustrated in Fig. 17, to a larger scale than that used in Fig. 6.

As illustrated in Fig. 17, each section of the trough 31, immediately above the corresponding buck-board or partition 38, is provided with a hopper or sump 51 to receive the material delivered by the corresponding section of the trough 31, which hopper or sump .is provided with an outlet 58 having a movable gate 59 to control the rate of flow of the delivered material, into the corresponding trough 39. The construction and operation of the gate 59 are more clearly illustrated in Fig. 84 showing one of the gates 59 in bottom view. As shown in Fig. 34, the gate is securedin place on the lower end of the outlet connection 58, by means of a pivot screw 50 so that it may be turned to more or less completely open the outlet connection 58, and the portion of the gate opposite to the screw 50, is preferably extended and provided with an aperture 6| for convenient engagement with'an operating rod that may be run through the corresponding,

trough 39 to engage and move the gate to establish the rate of flow desired in the trough 35. As shown in Figs. 17, 42 and 43, eachsection of the trough 31, above its hopper or sump 51,.

is provided on its bottom with a layer of porous material I31, for example moss, held in place by a screen I38, preferably of metal wire. The

screen supports a grid I39 of thin metal plates I39a and I391), which, as more clearly shown in Figs. 32 and 33., are in vertical planes crossing each other, to form compartments which are open at their upper and lower ends. Said compartments fill with sand and fine mineral matter which seep through the restricted passageways in the bottom of the sluiceway In above the trough 31, with the water and medium and fine metal particles diverted from the sluiceway flow. The diverted metal particles are thus directed downwardly by the diverted water, against the sand and mineral in the grid compartments, and a considerable part of the fine metal particles, is carried by the water through the sand and into the porous material I31, which retains much of said fine metal particles so brought into engagement with it; The porous material is removed from time to time, and the fine metal particles of value collected and retained by it, are recovered by any convenient means known to the art, and adapted to the purpose. The several sections of the trough 31 thus constitute in effect, rifile boxes which collect and retain part of the metal particles delivered to them, and particularly the fine particles of heavy rare metals, and at the same time they deliver for subsequent treatment, the lighter'metal particles they are not adapted to collect and retain. Thus these rifile boxes constitute separators operated by the specific gravity of the metal particles delivered to them. The lighter metal particles are carried from said rifileboxes by the water flowing through them, and are delivered to the troughs 39.

Theplates 35 and the bars 55 constitute in effect a plate grizzly which is particularly effec- 'fine material may tend to pack in said passageways and clog them.

As illustrated in Fig. 18, each of the rifle boxes 90 is provided with abottom of planks on which rifle blocks 5| are placed, which rifle blocks are preferably constructed and operate as above described. The manner of placing the rifle blocks 5| in the rifle boxes 40, is illustrated in plan view in Fig. 22, the rifle boxes 40 being narrower than the rifile boxes 34, on account of being located under the walk II, and there being preferably a greater number of them than there are of the rifle boxes 34. The metal particles finding their way through the restricted passageways between the bottom plates and supporting bars of sections D to J of the main sluiceway l0, which are not retained in the trough 31, are effectively brought into engagement with the mercury in the rifle blocks of the rifle boxes 40 and insofar as they are susceptible of amalgamation, they are efficiently retained thereby, as a result of the subdivision of the trough 31, and the control of the rate of flow through the troughs 39, it being desirable that each section of the trough 31 shall be no largerin any case, than to deliver the quantity of metal particles that can be efliciently treated in one of the rifle boxes 50, there being one of said rifle boxes for each section of the trough 31.

As illustrated in Figs. 23 and 24, the roller grizzly 29 preferably consists of a plurality of rollers, each comprising alternate rubberdisks 62 separated and spaced by smaller intermediate disks 63 said disks being mounted on a shaft 64 for rotation by suitable gearing 65 by the drive shaft 66 of the grizzly, for example by means of a sprockgearing 66, so that the upper surfaces of therollers move in the direction of flow of the water and mineral over the grizzly, indicated by the 'arrow 68 in Fig. 24. As illustrated in Fig. 24,

cleaning fingers 69 of suitable metal-are preferably mounted in the grooves between the larger disks 62, to prevent the mineral matter from packing in the grooves and interfering with the operation of the grizzly. The gearing 65 is illustrated in Fig. 25. The rollers are spaced from each other, and the disks 63 are of a thickness and diameter relatively to the disks 62, to provide clearance spaces betweenthe rollersjpermitting pieces of mineral of desired size to pass downwardly between the rollers.

metal particles that are not diverted through the I passageways in the bottom of sections D. to J of the main sluiceway Ill, are diverted withl the The resilient" nature of the rubber disks 62, permits pieces of water stream through the grizzly for subsequent treatment.-

As illustrated in Fig. 8, the roller grizzly 29 is preferably mounted at its upper end on a pivotal support 10, the lower end of the grizzlybeing supported by jack screws 1| so that the grizzly may be given different desired inclinations, depending upon the quantity of water flowing and the nature of the mineral matter carried by the water. Below thegrizzly 29, a shaking screen 12 is mounted in any convenient manner, for example, by links 13, so that the screen may be shakenlongitudinally by any convenient means, for ex-' ample, by-a connecting rod 14 extending from the upper end of the screen 12 to a-crank 15 carried suitablesource of power not shown. The screen 12 is of a mesh to permit the pieces ofmetal and 'mineral of desired size for subsequent treatment,

to pass through it, and serves to catch any over-' size pieces that may pass through the grizzly 29, anddeliver them from the tail end of the screen to the dump pile.

While the screen 12 illustrated, is of the shaking or reciprocating type, it will be understood that any known type .or kind of screen may be employed for this purpose, that will receive the upper end of a second chute 18 extending under the lower end of the main sluiceway In, to deliver its contents into the upper end of a third chute 19, which, as more clearly shown in Fig. '9, is divided at its lower portion to form the spouts 21 and 28 for delivering material received by the chute 19, to the distributing troughs 21a and 28a and from them to the control tanks l3 and M.

At the upper ends of the spouts 21 and 28;, a gate 80 is pivotally mounted at its lower edge, so that when it h'asthe position shown in full lines 'in Fig. 9, all of the water, metal particles and mineral delivered to the chute 19, are directed into the spout 21 and thus to the distributing trough 21a and by it to the control tank l3, whereas when the gate 80 is moved to its pos tion indicated by dotted lines in Fig. 9 at 80c, all of the material delivered to the chute 19, is directed by the gate 80 to the distributing trough 28a-and by it to the control tank H. Under some conditions, it is desirable to divide the material delivered tothe chute 19 and direct part of .it to each of the distributing troughs and this is readily accomplished by placing the gate 80 in"an intermediate position, as-i'ndicated in Fig. 9 by dotted lines at 80b.

The gate 80 thus affords a convenient means for using either control tank while the other is out of use, for example, while cleaning out the erably suflicient to take care of all of the material delivered to the chute 18, for normal or ordinary I by a shaft 16 rotated as desired by means of any flow in the sluiceway III, for example, while the mineral matter'is being washed from its natural deposit; at times said flow is materially increased, for example, in washing out pockets above the upper endof the sluiceway in which water has collected, producing a condition of"double heading, and when this-occurs, the increased flow .is effectively taken care of, by moving the gate 80 to a mid-position so that each control tank,

8 v will. receive apart of the material then delivered to the chute 18. without over loading either tank. The relation of the delivery end of the trough 30 to the chute 18 is illustrated in Figs. 8 and 9,

i of sections I to XII above referred to, so it is necessary to describe but one of said control tanks, for example the tank l3. As shown in Fig. 8, the tank i3 is provided with a bottom wall having two substantially level portions 13a and l3b adjacent its side walls and of the same width, and inclined portions I30 and I3d extending-upwardly and towards each other, from the inner edges of the portions l3a and l3b,'and meeting in a longitudinal linebentrally disposed beneath the trough 21a, the common upper edge of the portions I30 and i3d, being below the water level in the tank i3, and the portions Be and i3d constituting in effect a longitudinal partition in the tank.

As indicated in Fig. 9, and more clearly illustrated in Figs. 3'7 and 38, the distributing troughs are provided with gates at desired intervals, to discharge their contents into the corresponding control tanks, and since said distributing troughs are of the same construction, it is necessary to illustrate but one of them, for example, the distributing trough 28a shown in Figs. 37 and 38. As there shown, the troughlsa is provided in both of its side walls and throughout its length, with outlet openings 28b, and a gate 28c for each of said openings, mounted in suitable guideways for vertical movement toclose or open the corresponding outlet openings as desired. Each gate 280 may be held in any desired position by any suitable means, for example by a pin 28d extending through it, a plurality of holes 28c being preferably provided through the gate,to receive said pin for different desired amount ofopening of said gate.

The distributing trough 28a extends longitudinally of the tank I4 and centrally above it, and

as a result, the outlet openings in one side wallof said distributing trough and the gates associated therewith, control the delivery and distribution of .water 'metal particles and mineral, to the corresponding side portion of said tank,

and the outlet openings in the other side wall of said distributing trough and the gates associated therewith, control thedelivery and distributionof said material, to the other side portion of said tank, thereby providing 'for any desired distribution of said material to all parts df said tank.

.Itwill be understood that the outlet openings 28b and the gates 28c are illustrative only, and that'a'ny known type or kind of such devices may be employed, as desired.

Similarly, the water and the material carried thereby which are delivered'by the trough 21a to the tank i3, may be divided so that substantially half thereof is delivered above the bottom wall portion Ba, and the other half abpve the bottom wall portion lib, so that the metal particles and mineral matter may be divided into two substantially equal parts in the control tank I! for the subsequent treatments controlled by the control tank, and further, that the metal particles and mineral delivered to each side portion of the control tank, may bgdlstributed with so that .the water and the fine metal particles carried thereby, which flow over the side walls of the tank It, are caught by thegutters i9 and and directed to the sluiceways and 26. The controltank Ills practically level throughout its length to facilitate the delivery of the fine metal particles and mineral matter to the several riiile boxes I! and I8 supplied from the tank i3. To insure flow in the gutters I9 and 20 to their delivery ends, they are of gradually increasing depth from adjacent the spout 21, to the remote end of the tank, the relation of the gutter 20 to the tank l3 adjacent the delivery end 01' the gutter 20, being illustrated in Fig. 8a.

As shown in Fig. 8, each of the pipes 15 and it may be closed, as desired, by inserting in its upper end a plug 0, provided with a handle Ii I extending above the water level in the tank It, for convenient operation of the plug when the tank is in use. This permits shutting \off the supply of material to individual ones of the riille boxes I! and I8 as desired, for example, to clean out said boxes. It will be understoodthat there, is little flow in the tank i3, and as a result, sludge accumulates therein to a considerable degree. To insure againstthe sludge clogging flow toand through the outlet pipes i5'and it, each of said outlet pipes is preferably provided in the tank IS, with a clearing pipe H2; open at its upper and lower ends, and perforated at 20. above the sludge line in the tank, said clearing pipe being vertically supported so that its lower end is near and directed towards the upper end oi! the corre sponding outlet pipe. When the upper end of any one of the outlet pipes tends to clog with sludge, the relatively clear water delivered from the corresponding clearing pipe H2, breaks up and thins the sludge, and causes it to flow to and through the outlet pipe.

The pipes I6 01 each of the treatment sections Ito XII, deliver water and metal and mineral particles from above the bottom portion I312 of 'the tank l3, to one of the rime boxes i8 as illusa corresponding riiiie box H, but extending horizontally beyond-the delivery end of the Hide box.

i|,'to insure that the-waste matter delivered from any rii'lle box it, will not find its way into the corresponding riiile box l'l. Each of the riiiie boxes I! is provided adjacent its delivery end, with a sump 82 for collecting metal particles and mineral matter not otherwise retained by the" action of the riilie box, so that the sump may becleaned out from time to time, and such further treatment given the removed metal and mineral particles as may-be desired. Each of the riilie boxes I1 is similarly provided with a sump 83 and for the same purposes. The riiiie boxes I! and I8 are respectively provided with water pipes 84 and 85 for supplying fresh water as may be desired to. said rifle boxes, in addition to the water delivered to them from the control tank l3, to produce desired action and flow of the material in the rifle boxes. 1

The rifle boxes I! and I8 are of the same construction and operate in the same manner, and

it is therefore necessary to describe but one of them, for example, the rifle box i8 which isshown in plan view inFig. 26. As indicated in this figure, the rifle box is provided with rifle blocks 5| of the construction illustrated in Figs. 13, 14 and 15, or blocks l5l of the kind shown in Figs-39 and 40 may be used if preferred, so that the metal particles flowing through the rifle box may be amalgamated by the mercury contained in the grooves in the rifle blocks. Bearing in mind that the material delivered to the rifle box I 8 may consist in part of fine particles of rare metals, such as iridium, palladium, platinum, ruthenium and osmiridium, and that these rare metals do not readily amalgamate with mercury, I find it desirable to provide means in connection with each-of the rifle .boxes I! and i8, toelectrically charge the metal particles flowing through the rifle box, since I find by so doing that particles of some of the metals which otherwise would not freely amalgamate withfthe mercury,

be in a single piece or a plurality of pieces as I are caused to do so. To effect the electrical charging of the metal particles in the rifle boxes I! and I8, I provide each of them, as illustrated in Fig. 26, with electrodes or anode bars 86 which may conveniently be connected together in sections by transverse metal bars 81 from which supporting studs 88 extend upwardly through and are insulated from supporting cross pieces 89, so that the bars 86 are held above and near the upper surfaces of the rifle blocks. 'I'he'studs 88 are preferably connected with a positive conductor 90 extending to a suitable source of current supply, not shown, to deliver the requisite voltage and current to charge the metal particles passing through the rifle box i 8. With this ar-.

rangement, the rifle blocks 5! are preferably provided with metal studs 5ie as above described, to make contact with the mercury in the grooves in the rifle blocks and so constitute the mercury, the other electrode or cathode of the electric circuit. To make convenient electrical connection with the studs 5 i e, and yet permit the rifle blocks most convenient, connected with a plurality of insulated wires which in turn are. preferably connected with the negative conductor 92 extending from the source of current supply used to-produce current fiow through the water as it flows over the rifle blocks. The rifle box l8 thus in effect isan electrolytic cell in which the current flows from the anode bars.85 to the cathode .i studs Me, the tendency being, to carry the metal particles with the current flow and produce more intimate association between the' metal particles I and the mercury than would otherwise occur, as

a result of which, combination takes place be-. tween the mercury and some of the rarer metal particleswhi'ch would not occur without the electrical action described. I To facilitate removing the anode bars 86, for example to permit cleaning out the rifle blocks,

.each of'the supporting bars 89 may be hinged to one sidewall-of the rifle box l8,-as indicated at 89a in Fig. 35. 1

The anode bars and cathode studs illustrated in Figs. 26 and 35, may have any desired conformation and relation to eachother and to the grooves in the rifle blocks, the construction and relation that I prefer to employ being illustrated in Fig.

36. As there shown, the anode bars-86 besides being held just above the upper surfaceof the rifle block 5i, are considerablywider than they are thick and of wedge shaped cross section, so that their thin edges extend upstream of the water flowing in the direction of the arrow 93. This not only offers little restriction to the water fiowing in the rifle box, but in addition, the inclined lower surface of each of the anode bars 86, diverts the water passing below it towards the rifle blocks 5 I, and increases the agitating effect of the water flow, on the mercury in the grooves in the rifle blocks. It is desirable that the trailing edges of the anode bars 86, be conformed as illustrated in Fig. 36, or the equivalent, to produce stream line fiow, without forming eddy currents in the flowing water, which would retard its flow.

The electrical treatment of the metal particles, above described, is not required in all applications of my system, its use being desirable where certain of the metal particles'treated, are of a kind, or in a condition that renders their amalgamation with mercury difficult or impossible without special treatment, and where electrically charging the metal particles, suilicientiy changes these conditions to produce effective amalgamation of the metal particles. In some cases, the .metal particles are covered with films or coatings, for example, oily films or coatings of iron oxide,

which interfere with ready and eflc'ient amalgamation, and in such cases, I find that the electric current flow described, breaks up the film or'coating and facilities effective amalgamation of the. metal particles. Where'electrical treatment is employed, I find that direct current flow generally produces satisfactory results, although any kind of electric current may be used, that will best meet the requirements of any particular case.

therifle boxes, is preferably constructed at its delivery end, as indicated in Fig. 27 for the pipe 85 supplying fresh water to the rifle box l8 illustrated in Fig. 26; As shown in Fig. 27, the pipe 85 extends through the upper end wall of the rifle box it! and is then turned downwardly, and

Each of the pipes for supplying fresh water to between its lower open end, and the bottom of the rifle box iii, a spreader plate 96 is supported in any convenient manner, for example by arms from the lower end of the pipe 85, so that the water issuing from the pipe 85 strikes the plate 84 and of the rifle box Iii.

The fresh water added to any of the-rifle boxes as desired, and as above described, serves to break up the slime in said rifle box to produce effective flow therethrough, and results in the effective collecting and amalgamating of the metal particles in said rifle box. Each fresh water supply pipe is preferably profee is spread over the entire upper end of the bottom vided with a control valve as in icated in the F drawings, so located in said supply pipe as to be rifle blocks 5| is preferably sufliciently removed from the upper end of the rifle box, so that the water and mineral matter flowing into the box will not impinge directly upon said upper rifle blocks, and the space between said upper rifle blocks and the upper end of the rifle box may be filled with a block of suitable material 95, for example rubber, to absorb the impacts of the pieces of solid matter delivered into the rifle box and eliminate the wear that would otherwise occur, if the block 95 were made of non-resilient material. The shape of the grooves 5Ia in the rifle bloc 5|, described in connection "with Fig. 15, results in the action of the water currents flowing over each rifle groove 5Ia, on the mercury in the rifle groove, which is generally illustrated in Fig. 28 for one of said rifle grooves. As shown in Fig. 28, the position normally assumed by the mercury in a rifle groove 5Ia is illustrated for the body of mercury 99, shown in full lines, which, as indicated, preferably has a depth less than half the depth of the groove. A stream of water flowing over the upper edge of the rifle groove 5Ia. is illustrated at SL and part of this water stream follows the surface of the rifle groove as indicated by the arrows at 91a, to engage the front side and lower surface of the mercury body 96, which tends to press the mercury body upwardly and also against the concave vertical surface of the rifle groove. At the same time, another part of the water stream takes the course indicated by the arrows 91b, above the mercury body 96 and just below the sharp upper edge 5Ib, and down the concave side wall of the rifle groove. The water flowing along the path indicated by the arrows 91b, is thus directed downwardly between the concave surface of the rifle groove and the adjacent side of the mercury body 96, so that the water pressures produced on the opposite sides of the mercury body, tend to decrease the width of'the mercury body in the rifle groove 5Ia, and cause it to assume a distorted form indicated in dotted lines at 90a. It will be understood that the water flow over the rifle block 5| is not uniform or constant, due to pieces of mineral carried by the water stream causing variations in the flow and corresponding pulsating eflects of the water streams on the mercury body 96. The result .of this is a pulsating action of the mercury body 96, in the direction indicated by the arrow 98. ,This continual agitation of the mercury body I breaks up the surface film on the mercury and I consists of side and bottom walls of wood, held in cleans it, and results in intimate contact between the mercury and any metal particles carried by the water stream against the mercury, so that most effective amalgamation results, of all the metal particles that are susceptible of ama1gaends to their delivery ends. Each of these sluiceways, as illustrated for the sluiceway 25 in Fig. 31,

place by suitable'main frame members 99, I00

and IN, it being understood thatl each ,set of main frame members holds the walls o f gthe' two sluiceways 25 and 26 in place, mere beingfacommon vertical wall' I09'between said sluiceways. As illustrated in Fig. 31, the bottom wall oflthe sluiceway 25 is covered by a layer of porous material I02, for examplemoss, on which a metal screen I03 is laid to keep the moss in place. Ad- I 'jacent the side walls of the sluiceway, layers ,of

porous material I04 and I 05, for example moss, are placed and held against said side walls, by

metal screens I06 and I0'I. Rifle bar frames I08 are placed against the screens I03, I06 and I01.

I The moss is suflciently porous so that the water and the fine metal particles carried by it, flow freely through it, and at the same time the minute leaves of the moss engage and effectively ,retain the line metal particles coming into contact with them, which may in large part, consist of the rare'metals above referred to, or other metals if they are present, since the fine gold particles have already been largely, if not entirely removed. When the moss has received all of the metal particles it can effectively retain, it is removed from the sluiceway 25 by first removing the rifle bar frames I08, after which the screens I06 and I01 are removed, the moss layers I04 and I05 are removed, then the screen I03 is removed and the moss layer I02 is removed. Then the sluiceway structure is rebuilt as described, with fresh moss ready for further operation, and the valuable metal particles contained in the removed moss, are recovered in any desired manher well known in the art.

It will be noted in Figs. 29 and 30, that the upper end of the common side wall I09 of the sluiceways 25 and 26, ends a short distance from the corresponding end wall of said sluiceways, forming a common compartment for receiving materialto be treated, from the troughs 23 and 24, and directing it to either or both of the sluiceways 25 and 26. A gate I09a may be conveniently used to prevent flow to either of the sluice-- ways 25 and 26, as desired, for example the sluiceway 25, when it is desired to renew the lining of porous material or moss, of-said sluiceway, without interrupting the operation of the other of said sluiceways. Providing the sluiceways 25 and 26 with a common side wall I09 asdescribed, thus permits flow to either of said sluiceways to be stopped by said gate I09a, as desired, or by removing 'said gate from said sluiceways, flow may be permitted to both of them simultaneously, which may be desired under some conditions. r

From the above it will be observed that in the treatment sections A, B and C'above described, I provide means for effectively recovering coarse metal particles from-the material flowing through the main sluiceway I0, the conditions under which these recovering means operate, being readily adaptable to the effective recovery of such particles in any particular case. It will also be observed that the treatment in each of the sections A, B and C iseffected by diverting or .in that section, are returned to the flow stream in the main sluiceway at the end of said section,

for subsequent treatment, as desired. It will be understood that there may be as many of the treatment sections represented by the sections A, B and C, as are required to effectively recover the coarse metal particles.

Again, after the recovery of the coarse metal particles by the successivetreatments illustrated in sections A, B and C, means 'are provided, as illustrated insections D to J, for efiectively recovering the medium metal particles and some of the fine metal particles, and it will be noted that the means employed in each of these sections are readily adaptable to the requirements of any particular case in this connection, and that for each of these treatment sections, a part of the water of the flow stream in the main sluiceway I0, is diverted or by-passed, carrying with it the medium metal particles and more or less of the fine metal particles, so that effective recovery may these treatment sections, the water delivered to the treatment section from the main sluiceway i0, and the mineral and metal particles carried thereby that are no'trecovered in said treatment section, are returned to the main water stream for subsequent treatment, as desired.

In this connection, it will be understood that the restricted passageways provided through the ticuiar case, and that the length of the bottom of the mainsluiceway provided with these restricted passageways, may be as great as required to effectively accomplish this diversion from the flow in the main sluiceway, and further that there may be as many successive treatments represented by the treatment sections D to J, as are required to efiectively recover the metal particles referred to. f

It will also-be observed that my system of recovery provides means for recovering the fine metal particles illustrated, as described, by the trough 31, and by the treatment sections I to XII in connection with each of the control tanks,

and that for each of these treatment sections, a

part of thewater flow is diverted to the means employed in the correspondingtreatmentsection,

carrying with it the fine metal particles to here-- remaining particles 'of. fine tively recovered. r

It will beunderstood that the control tanks may have any size and shape required to effectively accomplish their intended purpose in any particular case, and furthermore that each control metal may be effectank may supply as many treatment sections asare found advisable or necessary in any particu-' larcase, and alsothat the special sluiceways referred to may have any size and proportions that are found tobe-gdesirable or necessary'to efiectiv'elyaccomplish their intendedlpurpose. It will 'thus'be seen that by mysystem I provide means for eifectively and efliciently recovering from the mineral matter delivered to the main sluiceway l0,'practically all of the particles of valuable metals that are in such condition that they can be recovered, and that where these valuable metal particles are in free condition, it is possible to recover practically all of them by using the recovery means described, adapted to the requirements of any particular case.

Another important result secured by my recovery system in its application to placer mining,

- is the protection of the recovery means from tamparing, and the protection of the recovered metal particles from theft. From the circumstances attaching to placer mining, the main sluiceway employed is usually open and unprotected, and where the usual practice of recovering the metals by riiiie bars in the main sluiceway is employed, theft is common. It will be observed that in accordance with my system, the means employed in I case, it is required to periodically rearrange the be accomplished by the means employed in these vseveral treatment sections, and that for each of stopped. Duringthese intervals of cessation of water flow through the main sluiceway, the bottom plates 32, the planks 4 4, and the cross beams 45 of the treatment sections A, B and C, may be quickly removed; affording access to the rillie blocks 5| employed in the rifiie boxes 34, and also to the'riflle sumps 53/ The construction of the riili-e blocks 5|, permits their ready removal, cleaning and replacement, so that the entire clean-up operation of the rifiie block's and riflle sumps, may readily be efiected during the interval of cessation "of the water-flow in the main sluiceway,

after which. the riflie blocks 5! are given fr'e'sh mercury charges, and the beams 45, the planks 44, and'the bottom plates 32 may be replaced for further operation of the main sluiceway, and all 4 without requiring any delay in the operation of further operation, and the metal particles in the r removed lining may be recovered by any suitable means known to the art.

It will --also be observed that in each of the treatment sections E to J, the means employed for recovering the metal particles, are located below the sluiceway l0 and the walk II, and enclosed by the'structure of the walk and main sluiceway,.

so that they are not accessible during the operation of the main sluiceway.

bottom plates 36 and the bars 55 of the sluiceway,

and the planks of the walk II are readily" removable, affording access to the treatment means of each of sections E to J, the recovering means .of the corresponding riilie boxes may be readily removed and replaced, the riflie blocks maybe provided with fresh mercury charges, and the bars 55, the plates 36 and the planking of the During cessationsj of flow in'the main sluiceway as referred to, the

' walk may be replaced, so'that the clean-up operaof shelter, so that access to them is impossible to unauthorized persons.

It will thus be observed that by my system, I

effectively protect the recovery means employed from tampering, and I also prevent theft of the metals recovered by the treatment means.

Unless otherwise specified, the structures described are preferably made of wood. In the several figures of drawings, excepting in connection with the treatment means employed in sections A, Band C, only the essential devices employed are illustrated, it being understood that suitable means are employed for supportingrand holding the several devices in the relative relations illustrated. It will also be understood in connection with the recovery means associated with'the control tanks, that convenient walks are preferably provided for affording access to said treatment means, which are not illustrated, as they do not constitute a part of the present invention, and may have any location and construction desired.

My system thus classifies the mineral and metal particles treated, and provides effective means for collecting and recovering the valuable metal particles of each classification, said means for each classification being particularly adapted to the recovery of metal particles of that classification. This is true regardless of the source of the mineral treated, or the manner in which said mineral is prepared for the recovering operations, since my apparatus and method may be effectively applied, wholly or in part, to the recovery of valuable metal particles from mineral matter, regardless of how said mineral matter is mined, of how it is supplied to my treatment apparatus,- and regardless of whether the mineral matter containing the valuable metal particles to be recovered, receives preparatory treatment or not, before delivery to my treatment apparatus, the only requirementbeing that the mineral matter delivered to my apparatus for treatment, shall contain metal. parnticles desired to be recovered and susceptible of recovery substantially as described. In some cases, one part ofthe apparatus and method described, may be suflicient to effect eflicient recovery of the desired metal particles, while in other cases another part or parts of said apparatus and method maybe needed to eiIect the desired recovery, depending upon the nature and condition of the mineral matter delivered to the treatment apparatus in any case, it being understood that any part or parts of my treatment apparatus and method described, may be used singly or in any desired combination, according to the treatment required in any case.

While I have shown my invention in the particular embodiment and 'asembodying the particular steps of treatment above described, it will be understood that I do not limit myself to these exact constructions and steps of treatment, as I may employ equivalents known to the art at the time of the filing of this application without departing from the scope of the appended claims.

' What I claim'is:

1. Ina system of the class described, the combination of a main sluiceway having restricted passageways through its bottom for diverting water and metal particles from said main sluicereturning the material collected therein to the flow stream delivered by said main sluiceway for further treatment.

2. In a system of the class described, the combination of a main sluiceway having restricted passageways through its bottom for diverting water and metal particles from said main sluiceway, a main trough under said main sluiceway for receiving the material so diverted from said main sluiceway, said main trough having'spaced transverse partitions dividingsaid main trough into sections, and a riflle box for receiving material delivered by each of said main trough sections, the bottom of said main sluiceway com prising laterally spaced transverse metal plates, intermediate metal bars each between and supporting adjacent ones of said plates, and means spacing the edges of said plates from said bars to form said restricted passageways.

3. In a system of the class described, the combination of a main sluiceway having restricted passageways through its bottom for diverting water and metal particles from said main sluiceway, a main trough under said main sluiceway for receiving the material so diverted from said main sluiceway, said main trough having spaced transverse partitions dividing said main trough into sections, and a riiiie box -for receiving material delivered by each of said main trough sections, the bottom of said main sluiceway-comprising laterally spaced transverse metal plates, intermediate metal bars each between and supporting adiacent ones of said plates, and sheet metal sepa I rators on the ends of said bars spacing the edges of said plates from said bars to form said restricted passageways.

4. In a system of the class described, the combination of a main sluiceway having restricted passageways through its bottom for diverting water and metal particles from said main sluiceway, a main trough under said main-sluiceway for receiving the material so diverted from said main sluiceway, said main trough having spaced transverse partitions dividing said main trough into sections, and a riilie box for receiving ma-'- terial delivered by each of said main trough sections, the bottom'oi said main sluiceway comprising transverse ,metal plates, intermediatev metal supporting bars, and means spacing the edges of said plates from said bars to form said restricted passageways, said bars having edge flanges extending under the edge portions of adjacent ones of said plates.

5. In a system of the class described, the combination of a main sluiceway having-restricted passageways through its bottom for diverting water and metal particles from said main sluiceway, a main trough under said main sluiceway for receiving the material so diverted from said main sluiceway, said main trough having spacedj transverse partitions dividing said main trough into sections, and a riflie box for receiving'material delivered by each of said main trough sections, the bottom of said main sluiceway comprising laterally spaced transverse metal plates, intermediate metal bars each between and supporting adjacent ones of said plates, and means spacing same direction as said main sluiceway for receiv-' ing the material so diverted from said main sluiceway, said main trough having spaced transverse partitions dividing said main trough into sec- 15 tions, and riflle boxes extending in the same direction as said main trough for receiving material delivered respectively by said main trough sec- I tions, the bottom or said main sluiceway comprising laterally spaced transverse metal plates, and 20 intermediate metal bars each between and supporting adjacent ones of said plates, said barshaving grooves in them to contain mercury.

7. In a system of the class described, the com-' bination of a main sluiceway-having restricted passageways through its bottom for diverting water and metal particles from said main sluiceway, a main trough under and extending in the same direction as said main sluiceway for receiving the material so diverted from said main sluiceway, said main trough having spaced transverse partitions dividing said main trough into sections riflle boxes extending in the same direction 7 as said main trough for receiving material delivered respectively by said main trough sections, a walk along said main sluiceway, said riilie boxes being located under said walk and enclosed thereby to prevent access to saidriilie boxes, and transverse troughs extending irom said main trough sections to said riflle boxes.

40 8. In a system or the class described, the com bination of a main sluiceway having restricted.

passageways through its bottom for diverting water and metal particlesi'rom said main sluiceway, a inain trough under and extending in the 45 same direction assaid main sluiceway for receiving the material so diverted from said main sluiceway, said main trough having spaced transverse partitions dividing said main trough into sections, riiiie boxes extending in the same direc- 50 tion as said main trough for receiving material delivered respectivelyby said main trough sec-- tions, 9. walk along said main sluiceway, said riiiieboxes being located under said walk and enclosed thereby to prevent access to said riilie boxes, and 55 transverse. troughs extending from said main trough sections to said riiiie boxes, each or said main trough sections having at its lower end a hopper for collecting material from said section,

. ,each or said hoppers having an outlet for delivertions, riiiie boxes extending in the same direction" as said main trough for receiving material delivered respectively by said main trough sections, a walk along said main sluiceway, said riiiie boxes n; being located under saidwalk and enclosed there-" by to prevent access to said riiiie boxes, and transverse troughs extending from said main trough sections to said riflie boxes, each 01' said main trough sections having at its lower end a hopper for collecting material irorn said section, each 5 or said hoppers having an outlet for delivering the 7 contents of said hopper to acorresponding one 01 said transverse troughs, and a gate on each of said hopper outlets and movable to control the rate of flow of material from said hopper to the" 10 corresponding one of said transverse troughs.

10. In a' system of the'class described, the combination 01' a main sluiceway having restricted passageways through its bottom, each or said passageways having portions at an angle to each other and eflecting slow flowmi water and metal particles therethrough from said sluiceway, a trough under'said sluiceway for receiving the water and .metal particles delivered from said passageways, and means, for recovering the metal. particles so received by said trough.

11. In a system of the class described, the combination oi a main sluiceway having restricted passageways through its bottom, each oi said passageways having portions at an angle to each other and effecting slow flow of water and metal particles therethrough from said sluiceway, and means for collecting the metal particles delivered irom said passagewaya. a

12. A main sluiceway having restricted passageways through its bottom, each of said passageways having portions at an angle to each other and effecting slow flow of water and metal particles therethrough tromsaid sluiceway.

13. A main sluiceway having a bottom comprising transverse metal plates, and intermediate metal bars each between adjacent ones oi said plates. theedges of said plates being spaced from said bars to form restricted passageways, each 0! said passageways having portions at, an angle to each other andefl'ecting slow flow or mineral particles therethrough.

14. In a system 01' the class described, the combination of a sluiceway h ving a bottom comprising transyerse metal p ates, intermediate '45 metal bars each between adjacent ones or said plates, and means spacing the edges or said plates from said bars to form restricted passageways, each of said passageways having portions "at an angle 'to' each other and effecting slow flow 5o oi mineral particles therethrough, and meansior collecting material flowing through'said passageways.

15. A main sluiceway having a bottom comprising transverse metal plates, intermediate metal barseach between adjacent ones 01' said plates, and metal separators on the ends of said bars spacing the edges of said plates from said I bars to form restricted passageways, each of said passageways having portions at an angle to each 0 other and eiiecting slow flow of mineral particles therethroush.

16. In a system oi the class described, the combination of asluiceway having a bottom comprising transverse. metal plates, intermediate metal bars each'between adjacent ones or said plates, and metal separators on the ends of said bars spacing the edges of said plates from said bars to term restricted passageways, each of said passageways having portions at an angle to each -other and eflecting slow flow of mineral particles therethrough, and means for collecting material flowing through said passageways.

1'7. A main sluiceway having a bottom comprising transverse metal plates, intermediate 

